Automatic slide changing and picture dissolving mechanism for still picture projectors



1952 C.-J. CADWELL ET AL 2,586,611

C'EURE DISSOLVING AUTOMATIC SLIDE CHANGING AND PI MECHANISM FOR STILL PICTURE PROJECTORS 3 Sheets-Sheet 1 Filed Dec. 51, 1948 Glare/Ice M 6adh/ell Pram M (5 5 5 W 1952 I c. .1. CADWELL ET AL 2, 86,611

AUTOMATIC SLIDE CHANGING AND PICTURE DISSOLVING MECHANISM FOR STILL PICTURE PROJECTORS Filed Dec. 51. 1948 3 Sheets-Sheet 2 Glarwce zlfiadn ell Frank Al. Aaamsan Feb. 19, 1952 c. J. CA ELL ET AL 2,586,611

AUTOMATIC SLIDE CHANG NG AND PICTURE DISSOLVING MECHANISM FoR STILL PICTURE PROJECTORS 3 Sheets-Sheet 5 Filed Dec. 31. 1948 Qwwem WW.

Clans/lee d aaarel Z Frank M. Aa'am 1W Patented Feb. 19, 1952 I AUTOMATICSLIDE CHANGING AND PIC- TURE DISSOLVING STILL PICTURE PROJECTORS Clarence J. 'Cadwell', Carpinteria, and Frank M. Adamson, Los Angeles, Calif., assignors to The Caldwell-Corporation, Beverly Hills, Calif., a corporation of California MECHANISM FOR Application December a1, 1943, Serial No. 68,672

This invention relates to the class of picture projecting machines and pertains particularly to projectors for still pictures, more especially those of the 35 mm. type.

A number of still picture projecting machines have slide mechanisms for shifting the pictures successively from a magazine to a position before the lens of the projector, such slide mechanism functioning to remove a previously presented picture when the succeeding one is advanced to position. In such projecting machines a, switch operated solenoid or rotary motor shifts or changes the slide automatically merely upon the pressing of a button by the attendant of the machine to energize the motor.

A principal object of the present invention is to provide a mechanism which may be made as an integral part of the machine or as an attachment, which is entirely automatic to energize the slide operating motor at predetermined intervals so that the changing of the pictures becomes entirely and completely automatic and does not even require the presence of an attendant at the machine to press a button forenergizing the slide motor.

Another object of the invention is to provide an improved dissolver or fade-out mechanism by means by which the light beam by which one 1 Claim. (Cl. 88-28) picture is being projected onto a screen is slowly shut off as the time approaches for making the change to another picture, until the shut-01f is very nearly complete and then gradually brought back to full intensity after the picture change has been effected so as to produce the illusion of the fading out of one picture and the gradual development of the succeeding picture.

A still further object of the invention is to provide mechanism of the character stated wherein the slide operating mechanism and the picture dissolving mechanism are coupled together for synchronous operation so that the slide operating motor is energized to effect the shifting of the slide and the changing of the pictures at the moment that the dissolver reduces the light beam to the minimum whereupon the dissolver begins to open up to restore thelight beam to full intensity and at the same time gradually develops the new picture.

A still further object of the invention is'to'provide a mechanism of the character stated which is operated by a synchronous motor for effecting the change of the picture at specific intervals of time as for example at one minute intervals.

Still another object of the invention is to provide in a dissolver mechanism a novel arrangement of cooperating sliding plates and a single motor actuated oscillating lever connected there'- with whereby said plates, having co'acting semicircular recesses, have such recesses gradually brought together to reduce the light beam intensity slowly and smoothly and gradually moved apart to slowly and smoothly increase the intensity of the light beam.

Another object of the invention is to provide a novel dissolver mechanism of the character above stated, which is constructed and arranged in a novel manner to be smoothly operated by a small synchronous motor of the type employed in electric clocks.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of the specification, with the understanding, however, that the invention is not to be limited to the exact details of construction shown and described since obvious modifications will occur to a person skilled in the art.

In the drawings:

Figure l is a view in top plan of a still picture projector machine showing the application thereto of a mechanism constructed in accordance with an embodiment of the present invention.

Figure 2 is a view in front elevation of the machine and the attached mechanism.

Figure 3 is a transverse sectional view taken in a vertical plane substantially on the line 33 of Figure 1 looking to the front or in the direction of the arrows.

Figure 4 is a detail view looking toward the forward side of the rear one of the two plates in which the iris plates move and showing the operating means for the iris plates.

Figure 5 is a view in front elevation of the two iris plates in operative relation and separated to form the full circular aperture.

Figure 6 is a diagram of the electrical circuit associatedwith the projector machine and the attached mechanism.

Figure '7 is a sectional view in a vertical plane taken substantially on the line l-l of Figure 2.

Figure 8 is a detail section taken substantially on the line 8-8 of Figure 4.

Referring now more particularly to the drawings the numeral l0 generally designates a still picture projector of a type designed to be oper-- ated manually through means of a side lever to effect the changing of the pictures orelectrically by means of a push button control, not shown, but connected with a current carrying cable I2 whereby a motor within the machine, when energized, effects the automatic transfer of a picture from a group stacked in the receiver l3 upon the top of the machine, to position in front of the lens of the projector. Simultaneously with this operation the picture previously on display, if any, is shifted into the bottom receiving corridor M. This mechanism is all of assaeu standard well known construction and does not require illustration or further description for proper understanding by those familiar with still picture projectors of the type under consideration.

It is also to be understood that while a projector has been specifically referred to and illustrated having the picture feeding magazine upon.

the top whereby the pictures are fed downwardly into position before the lens and then passed out to a receiving corridor or receptacle at the bottom of the 'machine, the invention is not limited in any respect to use upon machines of this character but may be used upon other machines where different automatic picture shifting arrangements may be employed.

The numeral l generally designates the lens I screw l9 which functions in an obvious manner to contract the end of the collar so as to firmly grip the lens barrel and maintain the mechanism in proper position thereon.

Integral with the forward end of the collar is the dissolver frame which is generally designated and which comprises the two rectangular plates 2| and 22 through which are formed the coaxial openings 23 and 24 respectively to form the light beam passage through the dissolver which is coaxial with the lens tube.

These plates 2| and 22 are secured together,

one in front of the'other, by the screws 25 and one of the plates, here shown as the plate 2|, has the face which opposes the other plate, re-

cessed as indicated at 26 whereby, when the plates are in position a shallow space is formed between them in which are slidably positioned the thin relatively shiftable iris plates 21 and 28.

The plate 21 is provided with an opening 29 of semi-circular form. This opening is formed between the ends of the plate 21. The cooperating plate 28 has formed in one end, a corresponding oppositely curved semi-circular recess or opening 30. These semi-circular openings have a radius equal to the radius of the interior of the lenstube l5 and when the plates 21 and 28 are separated to the maximum extent to which they are intended to move, the cut-out or semi-circw lar portions 293|l form a complete circular opening which is concentric with the lens tube, When the iris plates 21 and 28 are moved together to the maximum extent to which they are intended to move by the hereinafter described mechanism the recessed or cut-out portions of the plates run together as shown in Figure 2 to substantially shut off the light passage through the lenstube, leaving only a very narrow slit through which some of the picture illuminating light passes, as indicated at 3|.

Each of the iris plates 21-48 has formed therein at the right hand side of the dissolver, as seen from the front, a long arcuate slot which is adjacent to one longitudinal edge of the plate and a short straight slot having its long axis trans versely of the plate and adjacent to the other longitudinal edge. In the iris plate 21 the arcuate and transverse slots are designated 32 and 33 respectively and in the other plate 28 such arcuate and transverse slots are designated 34 and 35 respectively.

The back plate 2| of the dissolver unit is cut out in the end behind the slotted portions of the iris plates 21 and 28, as indicated at 36. Secured to the rear side of the plate 2| on the side of the opening 23 adjacent to the cut out 36, is the laterally directed triangular arm 31. The long axis or apex of this arm is on the longitudinal center of the dissolver unit and extended transversely through this arm 31 in the apex, is a rock pin or shaft 38.

Secured to the forward end of this rock pin 38, midway of its ends, is the rock arm 39 and each end of this rock arm carries the forwardly extending iris plate engaging pin 40. Thus it will be seen that the rock arm 39, being pivotally mounted midway between its ends, provides two oppositely directed cranks each of which carries a pin 40 and one of these pins extends through the arcuate slot 32 of the back or innermost plate 21 and engages in the short vertical slot 35 of the front plate 28, while the opposite pin 40 extends through the short vertical slot'33 of the back plate 21 and rides in the arcuate slot 34 of the front plate 28.

From the foregoing it will be obvious that when the rock arm 39 is at the limit of its swinging movement in one direction the iris plates 21 and 28 will be in fully closed position as shown in Figure 2 and when oscillated to the extreme position in the opposite direction the iris plates 21 and 28 will be in fully opened or separated position so as to permit the full beam of light to pass through the light tube of the projector and through the dissolver unit.

The rock pin or shaft 38 extends rearwardly and has secured thereto one end of a crank arm 42. The outer end of this crank arm has pivotally mounted thereon for oscillation on an axis paralleling the axis of the shaft 38, the pivot knuckle 43.

Secured to the collar 16 is a split ring 44 and this ring has secured thereto and supports a laterally extending bracket arm 45.

The bracket arm supports at one side of the projector and in a plane rearwardly of the plane of the dissolver unit 20, the vertical mounting plate which is generally designated 46 and which has the upper end rearwardly turned to provide a supporting flange 41 for manual or hand switches 48 and 49. These switches are preferably of the single throw toggle type and are controlled by the upstanding toggle arms? arldAS respectively.

, Secured to the rear side of the mounting plate. is a synchronous motor which is generaHy'des-J ignated 5|], the same being, as previously stated, of the type commonly employed in electric clocks and preferably operating at one revolution a minute on a 60 cycle current. I The motor 50 includes a shaft 5| which extends forwardly through the mounting plate and car ries a cam wheel 52 which carries a radially directed cam finger 53. Also secured to the motor shaft concentrically with the cam wheel 52, is the crank disk 54 which has cut into its periphery a radial slot 55 in which is secured a crank pin 55.

Connected with the crank pin 56 is an end of a crank rod or wire 51 which extends downwardly through and is secured to the crank arm knuckle 4s. A Secured to the forward side of the mountin plate directly beneath the cam wheel--52 is a micro-switch 58 which includes as a part of its structure a long horizontally positioned tongue 59 which lies in the vertical plane or the cam finger 53 and has its free end turned upwardly as indicated at 59' for engagement by the cam finger as the cam wheel rotates, whereby to efiect the depression of the tongue 59 and the closing of the switch. Obviously since the switch 58 is closed with each revolution of the cam wheel and since the motor 50 is of the one revolution per minute type, the switch 58 will be closed and opened once every minute. This switch functions to energize the picture slide operating motor and accordingly with the mechanism constructed and operating as described the picture will be changed at one minute intervals.

As shown the motor shaft crank 56 is very nearly 180 removed from the cam finger 53. Also the connection of the pivot knuckle 43 on the connecting rod or wire 57 is placed as high up as possible on the wire when the crank pin 56 is at its highest position. With this arrangement the upper end oi the oscillating lever 39 for the iris plates 27 and 28 will be at its extreme position toward the left as shown in Figure 4 and the opposite end will naturally be at the extreme position toward the right. In this position of the lever 39 the diffuser is fully or very nearly fully closed as shown in Figure 2. At the same time the micro-switch closing cam finger 53 will be directed downwardly against the upwardly curved end of the tongue 59, depressing the tongue and closing the micro-switch thereby energizing the picture slide operating motor. Consequently the picture will be changed when the difiuser is fully closed as will be readily understood.

Figure 6 illustrates the electrical connections between the electrical units of the invention and electrical parts of the projector. In this diagram the motor by which the picture changing slide is operated, is designated 60 and the incandescent lamp for the projector is designated 6|. As here clearly shown the manual switch 48 controls the starting and stopping of the synchronous motor 50 and the manual switch 49 controls the operation of the micro-switch 58 and consequently of the slide operating motor 60. The incandescent lamp 6| of the projector is, of course, in a separate circuit and forms no part of the present hook-up but it has been illustrated so as to complete the showing of the circuits.

In the operation of the present invention, after the desired number of pictures have been put in the supply magazine l3 and necessary electrical connection made at 62 with the current supply, the manual switches 48 and 49 are closed.

The closing of the switch 48 starts the synchronous motor to operating and puts into opera tion the dissolver unit which completes an opening and closing cycle once every minute as previously stated.

The closing of the manual switch 49 prepares the circuit to be periodically opened and closed by the cam finger closing the switch58 and accordingly each time the dissolver is fully closed the cam finger depresses the control tongue 59 to energize the slide motor 60 thereby causing the slide motor to remove the picture from the path of the light beam and insert a new picture from the magazine above.

Due to the fact that the opening and closing of the dissolver is gradual, the picture being exposed will be gradually reduced in intensity or caused to fade out until it is nearly obscured from view whereupon the new picture having been placed in position the dissolver will gradually open and cause the new picture to be slowly developed on the screen until it is displayed with full intensity.

From the foregoing it will be readily seen that the present invention provides a simple mechanism, readily connected in with the regular electrical connections for a projector of the type described, for fully automatically effecting the dissolving of a picture on display and developing a, new picture and sliding out the displayed picture and sliding in a new one at the correct moment when the light intensity is reduced to a minimum. The automatic dissolver and automatlc changer are coupled up in a novel manner for synchronized operation. At the same time, however, the electrical operation of the changer can be cut out without affecting the operation of the dissolver, so that the changer can be operated manually if desired, the application of the present device to the projector in no way affecting the construction, arrangement or operation of the manual mechanism forming a standard part of the projector machine.

It will, of course, be understood that the construction, arrangement and mounting means for the various parts have been here illustrated in a manner to present the invention with maximum clarity and that the construction, arrangement and mounting means for the parts may be suitably altered or refined in such a manner as not to detract from but to add to the aesthetic value of the projector as a whole.

We claim:

In a still picture projector, a motor operated picture changer, a second motor, means operated by said second motor for periodically energizing the picture changing motor, a dissolver mechanism operated by said second motor synchronously with the picture changing operating motor, said second motor continuing to operate said dissolver mechanism during the periods of inoperation of said picture changing motor, a pair of switches connected in series with the said picture changer motor, one of said switches having a movable contact element, a cam element mounted for rotation by said second motor and adapted to actuate said movable contact element whereby to periodically effect the energizing and de-energizing of said picture changer motor whenever the other of said switches is closed, and another switch in series with the first named switches for controlling the operation of said second motor independently of said picture changer motor.

CLARENCE J. CADWELL. FRANK M. ADAMSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 564,177 Hastings et al July 14, 1896 941,752 Ashley Nov. 30, 1909 1,172,628 Partington Feb. 22, 1916 1,436,370 Thomas Nov. 21, 1922 1,519,808 Christensen Dec. 16, 1924 2,021,963 Owen Nov. 26, 1935 2,076,924 Spindler Apr. 13, 1937 FOREIGN PATENTS Number Country Date 628,637 France July 4, 1927 

